Concerning a tire for large construction vehicles used in mines and the like, there has been a problem that early progress of wear, particularly in side portions of around ⅛ to around ¼ of a tread width from tread ends, causes partial wear. This kind of tires is usually provided with a crossing belt at a crown portion of a carcass to an outer side in the tire radial direction, and the crossing belt is formed by laminating at least two of inclined belt layers, which are made of a plurality of cords being extendingly inclined with respect to the tire equatorial plane, in a direction where the cords are crossing within the inclined belt layers. When the tire has this sort of a crossing belt and rotates with load, the crossing belt deforms in a tread ground contact area accompanied by so-called pantograph movement, in which crossing angles of the cords vary between the laminated layers. As the crossing belt deforms, rubber deformation will occur in the ground contact portion during a series of behavior of the tread ground contact surface from stepping into to kicking out the road surface. This rubber deformation is prominent, in particular in the above stated side portions so that a rubber slipping quantity increases when kicking out. As a result, wear is early progressing on these side portions.
In order to improve wear resistance of tires, a countermeasure has conventionally been taken that a tread rubber gauge is thickened to prolong a service life against wear. However, this countermeasure is considered to increase a volume of the tread rubber, which may worsen heat release property when driving and cause troubles such as heat separation and the like.
In addition, Patent Document 1 discloses a technique for suppressing tread rubber deformation in the tire width direction and thus wear in portions extending from tread ends to ¼ of a tread width and peripheral portions thereof (so-called ¼ point portions) as a preventive means for the partial wear, by disposing tire-circumferential narrow grooves from the tire equator beyond the ¼ points of the tread width towards outer sides in the tire width direction, in addition to a plurality of lug grooves disposed at an interval in the tire circumferential direction and extending in the tire width direction.